Square is up 200 percent in the last year and has more room to run. Here's why

Square shares just saw one of their best days since the company went public, and some market participants see further upside for the stock.

The mobile payment company, which has soared 198 percent over the course of the last year as investors have begun looking at the stock as somewhat of a bitcoin proxy, hit an all-time high in Monday trading as it surged nearly 10 percent. Monday's session was the stock's fifth-best ever, behind two sessions in 2016, one session in 2017 and the day of its initial public offering in November 2015.

In a weekend report, Ari Wald, Oppenheimer head of technical analysis, wrote in a note to clients that Square — along with the broader technology sector — is technically positioned to post further gains. Here are his reasons.

The S&P technology sector is breaking to the upside relative to the broader index, and its strength has been broad-based across both market capitalizations and sub-industries. Its resilience against rising interest rates, too, has been notable.